1. Field of the Invention
The present invention relates to a power converter including an active converter capable of obtaining an arbitrary DC (direct current) voltage, and more particularly, to a rush current suppressing operation.
2. Background Art
In an ordinary converter circuit, a current limiting resistor is provided in series with a smoothing capacitor, such that a rush current at the time of power-on is suppressed, and is bypassed through a current limiting resistor by a switching unit such as a relay at a steady state such as at the time of energization of a load (for example, refer to FIG. 4 of JP-A-10-271668).
In addition, there is disclosed a power converter in which at the time of instantaneous power failure, a voltage between both ends of the smoothing capacitor and a predetermined reference voltage are compared to each other, and based on a result of this comparison, a switching element connected in parallel with the current limiting resistor is controlled, such that the rush current is suppressed (for example, refer to JP-A-05-316640, Page 2).
In addition, there is disclosed a method of limiting the rush current in which the instantaneous power failure is detected by monitoring a zero cross of an AC (alternating current) voltage, the time of the instantaneous power failure that is permissible is calculated based on an electrostatic capacitance of a smoothing capacitor and a load current, and a switching operation of a relay connected in parallel with the current limiting resistor is controlled (for example, refer to JP-A-10-271668, Page 2).